The amino acid, L-theanine (N-ethyl-Lgluatmine, or theanine) is a major amino acid uniquely found in green tea. This compound has several physiological effects. L-Theanine is known, for instance, for having anti-anxiety effects in humans and animals. L-Theanine is also believed to act as a GABA agonist after being ingested (P. J. Nathan, et al., J. Herb. Pharmacother., 2006; 6(2):21-30). GABA (4-aminobutanoic acid, or γ-aminobutyric acid) is an endogenous neurotransmitter in the central and peripheral nervous systems.
Gastro-esophageal reflux disease (GERD) is an upper gastroesophageal tract disease. Certain useful therapies have been directed toward reducing gastric acid secretion, such as by use of a gastric acid inhibitor such as either a proton pump inhibitor or a histamine H(2)-receptor blocker (H(2)-blocker), or by otherwise lowering pH in the stomach such as by use of an antacid. GERD is believed to be a result of periodic lower esophageal sphincter relaxations (PLESR, or TLERS (“transient lower esophageal sphincter relaxations”)), and/or generalized diminished lower esophageal sphincter tone (A. Meining et al, Dis Esophagus 2004; 17(2):155-8). It has been shown that increasing GABA receptor activity, increases lower esophageal sphincter tone and reduces lower esophageal sphincter relaxations (P. J. Hornby et al., Gastroenterol. Clin. North. Am., 2002 December; 31(4 Suppl):S11-20, v-vi).
U.S. Pat. No. 6,117,908 describes that receptors for GABA have traditionally been divided into GABAA and GABAB receptor subtypes. GABAB receptors belong to the superfamily of G-protein coupled receptors. GABAB receptor agonists are described as being of useful in the treatment of CNS disorders such as muscle relaxation in spinal spasticity, cardiovascular disorders, asthma, gut motility disorders such as irritable bowel syndrome, and as prokinetic and anti-tussive agents. GABAB receptor agonists have also been disclosed as useful in the treatment of emesis (WO 96/11680), and as reflux inhibitors (U.S. Pat. No. 6,117,908). This latter patent document includes a description of the GABAB agonist baclofen, among other compounds, as potentially useful reflux inhibitors.
The citations above, shall not be construed as an admission that such reference is available as prior art to the present invention.